Physiological measuring system comprising a garment in the form of a sleeve or glove and sensing apparatus incorporated in the garment

ABSTRACT

A measuring system for measuring electrocardiogram signals comprises a diagnostic garment with ECG electrodes that may assume the form of a sleeve or glove. A disposable version of the glove can be inflated. By using an inflatable glove, the contour of the body is automatically matched by the contour of the glove. Samples from the ECG electrodes positioned on a diagnostic garment are compensated so that the samples better approximate samples from EEG electrodes that are positioned at classical locations. Also, samples from ECG electrodes are compensated to reduce signal noise resulting from positioning the ECG electrodes on the diagnostic garment.

CROSS REFERENCE TO RELATED APPLICATIONS

This is a continuation-in-part utility application based upon,incorporating by reference and claiming priority to application Ser. No.11/742,904 (now abandoned), filed May 1, 2007 entitled “PhysiologicalMeasuring System Comprising a Garment in the Form of a Sleeve or Gloveand Sensing Apparatus Incorporated in the Garment” which is a divisionalof application Ser. No. 10/899,484 (now abandoned), filed Jul. 26, 2004entitled “Physiological Measuring System Comprising a Garment in theForm of a Sleeve or Glove and Sensing Apparatus Incorporated in theGarment”, which is a continuation-in-part of application Ser. No.10/324,303, filed on Dec. 20, 2002 entitled “Physiological MeasuringSystem Comprising a Garment in the Form of a Sleeve or Glove and SensingApparatus Incorporated in the Garment” and granted as U.S. Pat. No.6,842,722 on Jan. 11, 2005, application Ser. No. 10/324,303 is acontinuation application of application Ser. No. 10/117,250 filed Apr.5, 2002 entitled “Physiological Measuring System Comprising a Garmentand Sensing Apparatus Incorporated in the Garment” and granted as U.S.Pat. No. 6,516,289 on Feb. 4, 2003, application Ser. No. 10/117,250 is acontinuation of application Ser. No. 09/359,340 (expressly abandoned),filed Jul. 21, 1999 entitled “Physiological Measuring System Comprisinga Garment in the Form of a Sleeve or Glove and Sensing ApparatusIncorporated in the Garment”, application Ser. Nos. 11/742,904;10/899,484; 10/324,303; 10/117,250, and 09/359,340 are incorporatedherewith by reference and for which priority is claimed.

BACKGROUND OF THE INVENTION

The field of the invention is in the design of devices for theacquisition, storage and transmission of multiple physiologicalparameters from human subjects to be monitored in hospitals, clinics,doctor's offices as well as in remote locations (home environment, workplace, recreational activity, etc.) or unnatural environments(under-water, outer space, etc.).

The conventional acquisition of a human electrocardiogram (ECG) requiresthe recording of the time dependent fluctuations in the cardiacelectrical activation from 12 different angles on the human torso (6 inthe frontal plane and 6 in the horizontal plane) the so-called 12 leadECG. Classically, this procedure involves the placement on the humanbody of at least 10 electrodes at various predefined anatomicallocations.

Deviation from the predefined, worldwide, conventional localization ofthese electrodes may result in the acquisition of false data, possiblyleading to misinterpretation and misdiagnosis. Even in the hospital orclinic environment, the correct and stable placement of the ECGelectrodes, specifically the “chest leads” or “V leads” is oftenproblematic, unless one applies six adhesive electrodes on the patient'schest. This is an impractical method in many circumstances due mainly tofinancial and patient inconvenience considerations. This problem isamplified in the attempts to record a full diagnostic 12 lead ECG in aremote location since the correct positioning of the electrodes by theexaminee himself or by available laymen bystanders (family members,friends, etc.) is usually difficult and unreliable and thereforeimpractical.

To overcome this problem and to allow for the accurate acquisition of a12 lead ECG in the ambulatory environment, various devices wereconceived. Such devices include various forms of vests, girdles,adhesive and non-adhesive patches and other devices with incorporatedelectrodes allowing for the placement of the ECG electrodes on thepatient's chest. However, most of these devices are cumbersome to useand have therefore not been universally accepted. Moreover, thesedevices do not lend themselves to the integration of other sensors andinstrumentation for the simultaneous acquisition of other importantphysiological data (blood pressure, Sp02, etc.), such data being veryuseful for the purpose of ambulatory telemedical follow-up of patientsin their own environment (home, workplace, recreational activity, etc).

SUMMARY OF THE INVENTION

The invention proposes to integrate a multitude of sensors and measuringdevices in a diagnostic garment in the form of a glove or sleeve forrepeated continuous and simultaneous assessment of various physiologicaldata such as ECG, noninvasive blood pressure (NIBP), blood oxygensaturation (Sp02), skin resistance, motion analysis, an electronicstethoscope, etc. An important advantage of the glove or sleeve is thatit provides accurate, repeatable and conventional placement orlocalization of the ECG electrodes (specifically for the recording ofthe chest or V leads) by positioning the left arm of patient in anatural and very comfortable manner on the chest. Moreover, the glove orsleeve provides a means for simultaneous recording, storage andtransmission of a multitude of other physiological data without the needfor difficult manipulations. Furthermore, the incorporation of variousmeasuring tools or instruments into one device, i.e. glove or sleeve,allows for the reciprocal calibration and easy acquisition of important,integrated, physiological data, a feature presently almost unavailablein the ambulatory environment (e.g. beat to beat NIBP changes,integration of: heart rate, blood pressure, skin resistance and otherparameters for the assessment of autonomic balance, etc.).

With one aspect of the invention, samples from the ECG electrodespositioned on a diagnostic garment (e.g., a glove or sleeve) arecompensated so that the samples better approximate samples from EEGelectrodes that are positioned at classical locations. With anembodiment of the invention, a first mean QRS vector is selected from afirst plurality of mean QRS vectors associated with standard electrodesand second mean QRS vector is selected from a second plurality of meanQRS vectors associated with the diagnostic garment.

With another aspect of the invention, samples from ECG electrodes arecompensated to reduce signal noise that may result by positioning theECG electrodes on the diagnostic garment.

With another aspect of the invention, a disposable version of the glovecan be inflated. By using an inflatable glove, the contour of the bodyis automatically matched by the contour of the glove. The matchingcontours will allow for a close fit between the electrodes and the skin.

A further aspect of the invention relates to the inflatable glove whichis capable of assuming the contour of the body and which is alsodisposable. The contoured glove incorporates electrodes and thereby mayenable appropriate positioning of ECG electrodes.

Another aspect of the invention is the design of the inflatable glovewhich may be incorporated with a sling or a similar device such as asleeve or holder will be separable from and capable of appropriatelypositioning and holding the inflatable glove.

These and other objects, advantages, features and aspects of theinvention will be set forth in the detailed description which follows.

BRIEF DESCRIPTION OF THE DRAWING

In the detailed description which follows, reference will be made to thedrawing comprised of the following figures:

FIG. 1 depicts the classic locations for the placement of ECG electrodeson a human body for recording of a conventional 12-leadelectrocardiogram.

FIG. 2 depicts the central unit that includes all of the controlfunctions for the various devices incorporated in the glove or sleevedevice of the invention as well as on-line storage, analog to digitalconversion and transmission capabilities of all acquired data; twoblood-pressure cuffs (wrist and arm); and Sp02 and plethysmographicsensors (fingers).

FIG. 3 depicts the ventral aspect of the glove or sleeve deviceillustrating the suggested location of the various ECG electrodes topermit easy placement of the ECG electrodes at predefined locations on apatient's body for recording a diagnostic 12 Lead ECG. Furthermore, twosmall microphones are depicted on the ventral side of the glove to beconnected with the electronic stethoscope located in the central controlunit.

FIG. 4 depicts the ventral aspect of the glove or sleeve devicedepicting mainly the suggested location of other possible sensors forthe determination of other physiological data such as temperature, skinresistance, etc.

FIG. 5 depicts the advised positioning of the patient's left arm withthe glove or sleeve device on the patient's chest to ensure properlocalization of the 12 lead ECG electrodes for accurate and reproducible12 lead ECG recordings, as well as the proper positioning of anelectronic stethoscope. This arm position, aided by a neck sling whichmay also contain an additional ECG electrode, is natural and comfortableand therefore allows for prolonged, stable and continuous monitoring ofall desired physiological parameters.

FIG. 6 is a schematic circuit diagram of sensor inputs for the system.

FIG. 7 is a schematic mechanical system diagram of the ECG inputs andblood pressure inputs.

FIG. 8 is a schematic circuit diagram of the input circuitry for the ECGmeasurements.

FIG. 9 is a schematic circuit diagram for the overall system.

FIG. 10 shows a simplified representation of an exemplary ECG waveformthat is obtained from an ECG lead in accordance with an embodiment ofthe invention.

FIG. 11 shows an ECG waveform and an associated vector representation inaccordance with an embodiment of the invention.

FIG. 12 shows an Einthoven's triangle representing ECG leads inaccordance with an embodiment of the invention.

FIG. 13 shows a vector diagram for determining compensation parametersin accordance with an embodiment of the invention.

FIG. 14A shows a flow diagram for compensating for the positioning ofECG electrodes on a diagnostic garment in accordance with an embodimentof the invention.

FIG. 14B shows a continuation of the flow diagram shown in FIG. 14A.

FIG. 15A shows a flow diagram for compensating for signal noiseresulting from the positioning of ECG electrodes on a diagnostic garmentin accordance with an embodiment of the invention.

FIG. 15B shows a continuation of the flow diagram shown in FIG. 15A.

FIG. 16 shows apparatus for obtaining, transforming, and communicatingECG measurements from electrodes that are positioned on a diagnosticgarment in accordance with an embodiment of the invention.

FIG. 17 shows apparatus of a remote surveillance center for receivingand processing ECG measurements in accordance with an embodiment of theinvention.

FIG. 18 is a plan view of an inflatable sensor carrying device or gloveor sleeve designed to be placed upon the left hand and forearm of anindividual with appropriate electrodes positioned in accord with theteachings of the invention.

FIG. 19 is a plan view of the inflatable glove of FIG. 18 as viewed fromthe opposite side thereof.

FIG. 20 is a side view of the glove of FIGS. 18 and 19.

FIG. 21 is an opposite side perspective view of the glove of FIG. 18.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

As depicted in FIGS. 2-5, the garment of the invention is preferably inthe form of a glove or sleeve or combined glove and sleeve 10 and isfabricated from flexible material such as a nylon fabric that can fitsnugly, without causing discomfort, on a human hand, forearm and arm.The glove or sleeve 10 is sized to fit or conform to patient arm sizeand shape. A neck sling 12 is attached to the glove or sleeve 10. Theneck sling 12 is also adaptable and adjustable to the individual patientto ensure accurate positioning or elevation of the left arm on the chestof the patient for the proper placement of the ECG electrodes. Moreover,the neck sling 12 may include an additional ECG electrode 14 (FIG. 5).

Two blood-pressure cuffs 16, 18 are incorporated in the glove or sleeve10. One cuff 16 is positioned on the arm in the conventionalblood-pressure measuring location, the second cuff 18 is placed on theforearm. Special restraining straps 20 mounted on the outside of theglove are wrapped around the blood-pressure cuffs 16, 18 to allow properrestrainment during cuff inflation. The blood-pressure cuffs 16, 18 areconnected by a flexible tube 22, 23 to a central control unit or device24 for inflation, deflation, and measurement of blood pressure byconventional methodology and used in the automatic determination ofNIBP.

At least ten ECG electrodes 30 are attached to the glove or sleeve 10 asdepicted in FIG. 3. All of the ECG electrodes 30 except the LA electrodeface the patient's chest whereas the LA electrode 30 is in contact withthe skin of the left upper arm. The RA electrode 30 or its equivalent isplaced either on the index finger of the glove 10 in the neck sling 12,or in another suitable position. All of the electrodes 30 are wireconnected to the ECG recording device located in the central controlunit 24 retained in the sleeve 10.

The ECG electrodes 30 included the following features:

-   -   (a) An automatic electrolyte solution application device. In the        course of the recording of a conventional ECG, it is the routine        to manually apply an electrolyte solution or cream to the        contact surface between the skin and the recording electrodes to        cause a reduction of skin resistance and to improve the        conduction of the electrical current between the skin and the        according electrode. In the described glove or sleeve 10, each        electrode 30 includes means for automatic injection of an        electrolyte solution into each electrode 30 prior to the        acquisition of the ECG. This is achieved by connection of each        electrode to an electrolyte reservoir by means of connecting        tubes 32. Prior to the acquisition of the ECG recording, the        electrolyte solution will be automatically sprayed into the        electrodes 30 by pressure provided by a pump located in the        central control unit 24.    -   (b) A suction device for better electrode-skin contact: The ECG        electrodes 30 will be configured as suction electrodes 30 and        will be connected via suction tubes 34 to a pump located in the        central control unit 24. Once the glove or sleeve 10 is placed        on the chest in the proper position, an external signal will        activate the pump to create the needed negative pressure and        suction to maintain the proper electrode-skin contact. Following        the termination of the ECG recording, the negative pressure will        be abolished allowing detachment of the electrodes from the        patient's chest. The same or separate pumps may be utilized to        effect electrolyte application and the creation of electrode        suction.

A conventional IR SpO2 measuring device 36 is incorporated in the gloveor sleeve 10 and placed on one of the glove finger tips 38 to fit thepatient's finger. Blood SpO2 is determined using the conventionalmethods applied for this measurement and the results will be stored inthe central control unit 24.

A conventional finger Plethysmographic-measuring device 38 isincorporated in one of the glove fingertips 40 to fit on the patient'sfinger. An external restraining device 42 ensures continuous snugcontact with the finger to provide continuous beat to beat changes infinger blood volume variation. The finger plethysmograph is wireconnected to the central control unit 24. The signal is periodicallycalibrated using the conventional cuff blood pressure measurementsthereby allowing for continuous beat to beat blood pressure monitoring.

A thermistor 44 is incorporated in the glove or sleeve 10 and located onthe ventral surface of the arm in direct contact with the skin to allowthe determination of skin temperature. The thermistor 44 is wireconnected to the central control unit 24.

A conventional sensor 46 for the determination of skin resistance isincorporated in the glove or sleeve 10 and wire connected to the centralcontrol unit 24.

Two special microphones 50, 52 are attached to the ventral aspect of theglove or sleeve 10, one located over the base of the left lung and thesecond on one of the fingers for the simultaneous auscultation of bothlungs. Furthermore, the finger microphones 50, 52 can also be moved toenable auscultation of the heart and other organs. The microphones 50,52 will be connected to the central control unit 24 for recording andtransmission of the auscultatory findings.

Motion and force assessment devices 60, 80, 82 are incorporated in theglove or sleeve 10 mainly for the early detection of neurological andneuromuscular dysfunction. Sensors 60 assess passive and activefunctions such as:

-   -   (a) Force of muscular contraction (e.g., handgrip, arm flexion        and extension, etc.)    -   (b) Passive pathological arm and finger motion (Parkinsonian        tremor, flapping tremor, etc.).    -   (c) Assessment of active finger, hand or arm motion (rapid hand        pronation and supination, rapid finger motion, etc.).

The glove or sleeve 10 is equipped with a central control unit 24attached to the dorsal aspect of the glove or sleeve 10 (FIG. 2). Thegeneral function of this unit 24 is the collection, transformation,storage and transmission of all of the physiological data collected fromthe various devices incorporated in the glove 10. Moreover, the centralcontrol unit 24 includes mechanical and other devices such as pumps,injectors, etc., needed for the proper functioning of the incorporateddevices as described herein.

Specifically, the central control unit 24 includes the appropriatemeasuring element for each sensor. The measured data is digitized,stored and upon demand, made available for transmission by RF or IR orany other form of wireless telemetric transmission to a remotesurveillance center. Conversely, the central control unit 24 has theability to receive signals from a remote surveillance center for theactivation or deactivation and other control functions of the variousmeasuring devices incorporated in the glove 10.

In review, the glove 10 provides an unobtrusive stable platform forself-application of numerous physiological sensors using a glove and/orsleeve 10 and an optional neck support sling 12 to perform varioussimultaneous non-invasive on invasive health-care related measurementsfor use in the home, workplace, recreational, clinic or hospitalenvironment. The invention has the advantage over other methods ofsensor applications in that no prior knowledge of proper sensorplacement is required and that proper placement of the sensors on thepatient is assured. The sensor position is stable and reproducible. Theinvention improves the repeatability of measurements by insuring thatthe placement and distances between the various sensors remain constant.Moreover, the interplay between the various sensors can result in thecombination of data acquisition integration and analysis adding majorsophistication and improvement as compared to the individual use of eachmeasuring devices.

In further review, the glove/sleeve 10 together with the optional necksupport sling 12 contains one or more of the following measuringelements:

-   -   (a) An optical emitter and detector 36 attached to the index        finger of the glove 10 for the purpose of measuring the level of        oxygen saturation in the blood, and peripheral pulse (FIG. 2).    -   (b) A finger plethysmograph device 38 for continuous, beat to        beat, noninvasive arterial blood pressure measurement        (calibrated by the mean of the arterial blood pressure        determinations derived from both the wrist and arm NIBP devices)        (FIG. 2).    -   (c) Inflatable cuff and pressure cuffs or sensor 16, 18 located        in various locations on the arm and hand to measure brachial        radial or finger blood pressure for periodic (automatic or        manual) noninvasive blood pressure measurements (NIBP). These        NIBP measuring devices are also used to calibrating the optical        system used to measure continuous, beat to beat arterial blood        pressure as above mentioned (FIG. 2).    -   (d) A central control unit 24 for the acquisition and        transmission of the various bio-signals derived from the glove        sensors. This central control unit 24 which can be activated        locally by the patient or remotely by a monitoring center allows        for automatic or manual activation of any or all of the sensors.        The central control unit 24 provides amongst other: the initial        and repeated sensor calibration procedures, activation of a        built-in miniature pump for the creation of positive and        negative pressures, the reception of commands from the remote        control center, analog to digital conversion of measured data        and their transmission to the control center as well as any        other needed control functions (FIG. 2).    -   (e) A set of electrodes 30 (V1, V2, RA, RL) placed on the palmar        aspect of the glove 10 and/or the neck support sling 12 for the        purpose of simultaneous recording of a twelve-lead        electrocardiogram (FIG. 3).

(f) A method for automatic administration of an electric conductorsolution/cream to the electrodes 30 to reduce skin resistance andimprove ECG relating quality.

-   -   (g) A method of producing and maintaining a sufficient negative        pressure (suction) inside the ECG electrodes 30 to insure proper        contact between the ECG electrode and the skin (FIG. 3).    -   (h) A method of insuring proper contact between the ECG        electrodes 30 and the skin by the application of an air cushion        or a gel cushion around areas of the glove that are in contact        with the skin. The cushion is used to provide a body contour fit        (FIG. 3).    -   (i) A method such as a buckle connection 15 to adjust the sling        12 to ensure that the arm is held at the proper level for        accurate placement of the ECG electrodes 30 on the patients        body.    -   (j) A temperature sensor 40 placed in appropriate areas of the        glove/sleeve 10 for the purpose of measuring body temperature        (FIG. 4).    -   (k) An electrode or set of electrodes 46 placed in the palm area        of the glove for the purpose of measuring skin resistance (FIG.        4).    -   (l) An electronic stethoscope for the auscultation of lungs,        heart and other organs.    -   (m) Built-in measuring devices 80 in FIG. 4 in the glove fingers        for the accurate assessment of tremor and other normal or        neurological forms of finger motions.    -   (n) Built in measuring devices 80 in the glove 10 for the        determination of EMG.    -   (o) Built-in measuring devices 80 in the glove 10 for the        determination of nerve conduction.    -   (p) Built-in measuring device 82 for the determination of muscle        force (hand grip, extension, flexion, etc.).    -   (q) Built-in device 82 for the assessment of rapid/accurate        voluntary hand movement.    -   (r) The advised positioning of the patient's left arm on the        chest to ensure proper localization of the 12 lead ECG        electrodes of the glove for accurate and reproducible 12 lead        ECG recording is shown in FIG. 5. This arm position, aided by        the adjustable neck support sling 12, is natural and comfortable        and therefore allows for prolonged, stable and continuous        monitoring of all available parameters (FIG. 5).

FIGS. 6, 7, 8 and 9 are schematic drawings depicting the basic elementsdescribed above. FIG. 6 depicts the various sensors including the SpO2sensor 36, the plethysmography sensor 38, the temperature sensor 44,skin resistance probes 46, strain gauges 48, and stethoscope sensors 50,52. As depicted in FIG. 6, each of the inputs in amplified and, ifnecessary, filtered prior to being converted to a 24 bit analog todigital converter. The output of the analog to digital converter goesvia a control ASIC depicted in FIG. 9 to a dual port ram also in FIG. 9where it is processed and transmitted by a microprocessor and aninfrared communications to a stationary unit.

FIG. 7 depicts the various mechanical elements and connections for theECG electrodes and the blood pressure mechanical and electronic portionof the system. Each ECG electrode comprises a container that holds asaline solution or another lubricant. This solution is drawn into theelectrode via a vacuum system. A bleed valve closes the system and thenreleases the vacuum. The release of the vacuum will then release thelubricant or solution. Digital input output drivers control the vacuumpump and the bleed valve in response to signals that are provided fromthe ASIC control lines. In the embodiment disclosed, there are two bloodpressure cuffs, one associated with the wrist and one with the upperarm. A blood pressure pump (NIBP pump) pumps each cuff. A pressuresensor then measures the pressure in each cuff. The values from thepressure sensor are amplified, filtered and converted to digital valuesin the 24-bit analog to digital converter. The output of the analog todigital converter also passes through the control ASIC in FIG. 9 to thedual port random access memory unit where it is processed andtransmitted by the microprocessor and IR communications, for example, toa stationary unit.

FIG. 8 depicts the ECG analog input circuitry. Each electrode input isseparately amplified and ban passed filtered prior to conversion by a24-bit analog to digital converter. The analog to digital convertersignal passes through the control ASIC in FIG. 9 to the dual port RAMwhere it is processed and transmitted again by the microprocessor and IRcommunications to a stationary unit.

FIG. 9 depicts the digital circuitry in the system. The circuitryincludes the ASIC which has logic for the timing signals and fortransmitting or passing the digitized analog signals from the variousanalog to digital converters to the dual port RAM which sits on themicroprocessor. The microprocessor runs the software provided from theflash memory, collects data samples, performs basic analysis, controlsthe various valves and pumps and sends data to the central datacollector via IR communication. The described circuitry is but one wayto accomplish the goals and objectives of the use of the glove and/orsleeve of the invention.

Electrode Compensation

Embodiments of the invention enhance a vector representation of the ECGwaveforms. As will be discussed, methods and apparatuses provide foradjusting a vector representation of ECG signals to compensate forpositioning ECG electrodes on a diagnostic garment (e.g., theglove/sleeve as discussed above) rather than classically positioning theelectrodes on a patient's limbs as with standard ECG electrodes. Also,an embodiment of the invention compensates for additional signal noisethat may be imposed on the EEG signals resulting from the positioning ofthe EEG electrodes on the diagnostic garment.

Cardiac activity generates a measurable amount of electric current. Thecurrent is recorded through an electrocardiograph and displayed as anEEG waveform, the shape of which is governed by both the magnitude anddirection of the current flow. The EEG waveforms may be displayed asvectors whose trajectories also depict the magnitude and direction ofthe heart's impulses as will be discussed with FIG. 11. The average ofthese vectors for a particular heart cycle is called the mean QRS vectorand is displayed on a vector image as a solid arrow whose length is theaverage magnitude and whose angle is the average direction.

FIG. 10 shows a simplified representation 1000 of an exemplary ECGwaveform that is obtained from an ECG lead in accordance with anembodiment of the invention. In normal sinus rhythm, each P wave 1001 isfollowed by a QRS complex (comprising Q wave 1003, R wave 1005, and Swave 1007). The QRS complex represents the time it takes fordepolarization of the ventricles. Activation of the anterioseptal regionof the ventricular myocardium corresponds to the negative Q wave 1003.However, Q wave 1003 is not always present. Activation of the rest ofthe ventricular muscle from the endocardial surface corresponds to theremainder of the QRS complex. The R wave 1005 is a point when half ofthe ventricular myocardium has been depolarized. Activation of theposteriobasal portion of the ventricles give an RS line. The normal QRSduration is approximately from 0.04 seconds to 0.12 seconds measuredfrom the initial deflection of the QRS complex from the isoelectric lineto the end of the QRS complex. The QRS complex precedes ventricularcontraction.

FIG. 11 shows an ECG waveform and an associated vector representation inaccordance with an embodiment of the invention. FIG. 11 shows QRScomplex 1101 being represented as vectors 1003 (in relation toEinthoven's triangle 1107 as will be discussed) whose trajectories alsodepict the magnitude and direction of the heart's impulses. The averageof these vectors for a particular heart cycle is called mean QRS vector1105 and is displayed on the vector image as a solid arrow whose lengthis the average magnitude and whose angle is the average direction. QRScomplex 1109 corresponds to a subsequent heart cycle that can bepresented by another set of vectors.

Experimental studies involving hundreds of patients compare 12-lead ECGrecordings with both standard electrodes and with electrodes positionedon a diagnostic garment. The diagnostic garment may assume a garmentthat fits on a portion of a patient's body and may assume a form of aglove/sleeve as shown in FIGS. 2 and 3. An exemplary embodiment of theinvention utilizes PhysioGlove™, which is a glove/sleeve that fits overa patient's left arm and left hand.

The standard “12 lead ECG” utilizes the three standard limb bipolarleads (lead I, lead II, and lead III), three augmented limb leads, andsix precordial unipolar leads. The augmented leads are the same as thestandard leads, except that the augmented leads are compared to ahypothetical null value that corresponds to a central point over theheart where no fluctuations in potential can be measured. The null pointis actually mathematically determined using the electrical potentialsgenerated by the other 2 leads. The lead on the left arm is known as anaVL lead, the lead on the right arm as an aVR lead, and the lead on theleft leg as an aVF lead. Precordial leads are leads fanning across thechest. Precordial leads (V1, V2, V3, V4, V5, and V6) give more specificinformation about electrical conduction in the heart than the limbleads.

Comparing the locations of EEG electrodes 30 on diagnostic garment 10shown in FIG. 3 and the classic positioning of ECG electrodes as shownin FIG. 1, one observes that the locations of the corresponding EEGelectrodes are different. In order to better approximate the signalsfrom the classic positioning of ECG electrodes, the ECG signals from theEEG electrodes on diagnostic garment 10 may be compensated as will bediscussed. In particular, experimental studies indicate variations inthe EEG waveform are caused by positioning the LL electrode ondiagnostic garment 10 rather than on the left leg.

FIG. 12 shows an Einthoven's triangle 1200 representing (modeling) ECGleads 1207, 1209, and 1211 in accordance with an embodiment of theinvention. Lead I 1207 represents the electrical potential between LA(left leg) electrode 1203 and RA (right arm) electrode 1201. Lead II1209 represents the electrical potential between LL (left leg) electrode1205 and LA electrode 1203. Lead III 1211 represents the electricalpotential between LL electrode 1205 and RA electrode 1201. (RA electrode1201, LA electrode 1203, and LL electrode 1205 correspond to RA, LA, andLL electrodes 30 shown in FIG. 3.) From Einthoven's triangle 1200, onecan determine one lead from the other two leads by the followingrelationships:Lead I=Lead II−Lead III  (EQ. 1A)Lead II=Lead I+Lead III  (EQ. 1B)Lead III=Lead II−Lead I  (EQ. 1C)

Null point 1219 is a hypothetical “null” value that exits at a centralpoint over the heart where no fluctuations in potential can be measured.The “null point” is actually mathematically determined using theelectrical potentials generated by leads 1207, 1209, and 1211. Augmentedleads aVR 1213 (corresponding to the right arm), aVL 1215 (correspondingto the left arm), and aVF 1217 (corresponding to the left leg) aremeasured with respect to null point 1219. Augmented leads 1213, 1215,and 1217 can be expressed in terms of standard leads 1207, 1209, and1211. For example, aVF can be expressed as:aVF=0.5*Lead I+Lead III  (EQ. 1D)

Experimental results suggest that the mean QRS vector representing theQRS complex obtained from the patients using the diagnostic garmentvaries when compared with the mean QRS vector obtained from patientsusing standard electrodes. Experimental results also suggest that whenthese differences are compensated for, one can obtain an ECG waveformanalogous to the one obtained using the standard electrodeconfiguration.

FIG. 13 shows a vector diagram 1303 for determining compensationparameters in accordance with an embodiment of the invention. Analyzinga plurality of QRS complexes, vector 1301 is the selected mean QRSvector with standard electrodes (corresponding to the ECG electrodesshown in FIG. 1) and vector 1303 is the selected mean QRS vector withelectrodes positioned on the diagnostic garment (e.g., glove/sleeve 10as shown in FIG. 2). The selection of mean QRS vectors will bediscussed. Angle 1351 (Φ−α) and angle 1353 (α) are used to determine acompensation factor as will be discussed.

An analysis of the mean vector of the QRS complex is made from any twoof the three standard leads. In the embodiment, leads I and III areused. However, other embodiments of the invention can use lead II andlead III or lead I and lead II. The compensation process is a two-stageprocedure with each stage involving a series of steps:

Stage I—Determine Compensation Parameters:

-   -   Select an ECG time interval with several QRS complexes.    -   Find the average vector angle for these QRS complexes. Each QRS        complex is associated with a mean QRS vector (e.g., vector 1105        as shown in FIG. 11). A first plurality of mean QRS vectors is        associated with the standard electrode configuration (as shown        in FIG. 1) and a second plurality of mean QRS vectors is        associated with the garment electrode configuration (as shown in        FIG. 3).    -   Select the QRS complex with the angle closest to the average. A        first selected mean QRS vector is selected that is closest to        the average of the first plurality of mean QRS vectors and a        second mean QRS vector is selected that is closest to the        average of the second plurality of mean QRS vectors.    -   Find the compensation coefficient (k1), where        k1=Cos Φ/Cos(Φ−α)  (EQ. 2)    -   This coefficient will be used in Stage II for performing the        compensation. The angles Φ and Φ−α correspond to the angles        shown in FIG. 13.

Stage II—Apply the Compensating Algorithm:

-   -   The glove is a DSP device transmitting N samples per second to        the receiver where N is the sample rate.    -   Each sample contains Lead I and Lead III voltages.    -   The other limb leads are combinations of these two leads.

During Stage 2, the limb lead values are compensated using the followingmatrix formula:

$\begin{matrix}{{\begin{pmatrix}{{Lead}I}_{New} \\{{Lead}{III}}_{New}\end{pmatrix} = {{kA}^{- 1}{{BA}\begin{pmatrix}{{Lead}I} \\{{Lead}{III}}\end{pmatrix}}}}{{{where}\begin{pmatrix}{{Lead}I} \\{{Lead}{III}}\end{pmatrix}}\mspace{14mu}{and}\mspace{14mu}\begin{pmatrix}{{Lead}I}_{New} \\{{Lead}{III}}_{New}\end{pmatrix}}} & \left( {{EQ}.\mspace{14mu} 3} \right)\end{matrix}$are the columns of lead voltages before and after the compensation,respectively. The compensation associated with Equation 3 uses thefollowing matrix values:

$\begin{matrix}{A = \begin{pmatrix}1 & 0 \\0.5 & 1\end{pmatrix}} & \left( {{EQ}.\mspace{14mu} 4} \right) \\{B = \begin{pmatrix}{\cos\;\alpha} & {{- \sin}\;\alpha} \\{\sin\;\alpha} & {\cos\;\alpha}\end{pmatrix}} & \left( {{EQ}.\mspace{14mu} 5} \right) \\{{k\; 1} = {\cos\;{\Phi/{\cos\left( {\Phi - \alpha} \right)}}}} & \left( {{EQ}.\mspace{14mu} 6} \right)\end{matrix}$

Matrix A has an inverse

$A^{- 1} = {\begin{pmatrix}1 & 0 \\{- 0.5} & 1\end{pmatrix}.}$The compensation coefficient k1 is defined in Equation 2. The determinedcompensation is applied to every ECG sample provided by the diagnosticgarment. The compensated waveforms/reports are hence obtained.

While the exemplary embodiment selects one of the mean QRS vectorsclosest to an average of a plurality of mean QRS vectors, anotherembodiment can select a resulting mean QRS vector with anothercriterion. Also, another embodiment may determine a resulting mean QRSvector that corresponds to an average of the plurality of mean QRSvectors even though the resulting mean QRS vector does not correspond toactual measurement data.

The electrical signal from the heart's natural pace maker starts in whatis called the SA (sinoatrial) node located in the right atrium travelsthrough the right atrium to the ventricles (i.e. the lower chambers ofthe heart). The electrical signals cross a junction called the AV(atrialventricular) node going from the atruim to the ventricles. Fromthe AV node the electrical signal travels through a path called thebundle of His that splits into two paths one on the left lower chamberand one on the right lower chamber. Each path is called a bundle branch.The electrical signals from the bundle branches causes the ventricles tocontract. Normally both ventricles contract simultaneously. If one ofthe bundle branches is damaged then the blockage blocks or slows theelectrical signal on one of the paths. The blockage of the electricalsignal is called a bundle branch block. A left bundle branch block(LBBB) blocks the signal on the left side while a right bundle branchblock (RBBB) blocks the signal on the right side. Patients that have abundle branch block do not require compensation as described above.Thus, a separate algorithm may be used to detect those patients so thattheir ECG waveforms are not compensated.

ECG waveform noise reduction is performed in two stages, in which thesignal noise results from positioning the ECG electrodes on thediagnostic garment.

Stage I—Determine the Parameter for the Compensation Filter

-   -   Select an ECG time interval with several QRS complexes.    -   Calculate Mod_Lead I=V6−V1 values. Electrodes V6 and V1 are        positioned on the diagnostic garment as shown in FIG. 3.    -   Define the AVG (R(Lead I)) and AVG (R(Mod_Lead I)) for the        selected time interval. R is a parameter representing the height        of the QRS complex peak over the isoelectric line. R is a        parameter representing the height of the QRS complex peak over        the isoelectric line. In the embodiment, R corresponds to the        height of the R wave 1005 as shown in FIG. 10.    -   Determine the compensation coefficient k2, where        k2=AVG(R(Lead I))/AVG(R(Mod_Lead I))  (EQ. 7)    -   The compensation coefficient k2 will be used in Stage II for        performing the compensation.

Stage II—Apply the Compensating Algorithm

The glove transmits Lead I, Lead III, and V1 to V6 voltages. Leadpotential VL, which is a voltage between the LL electrode and the centerof Einthoven's triangle, is given by.VL=LL−(LL+LA+RA)/3  (EQ. 8)

VL voltage may also be obtained from the combination of the existingleads:VL=(Lead I+2*Lead III)/3  (EQ. 9)

The compensated values for Lead I and Lead III are determined by:Lead I_(New) =k2*(V6−V1)  (EQ. 10)Lead III _(New) =−k2*(V6−V1)/2+3/2(VL)  (EQ. 11)

where Lead I_(New) and Lead III_(New) are values after compensation, VLis the previously defined voltage, and k2 is the compensationcoefficient.

FIG. 14A shows a flow diagram 1400 for compensating for the positioningof ECG electrodes on a diagnostic garment in accordance with anembodiment of the invention. If step 1401 determines that a patient isdiagnosed with a bundle branch block (as previously discussed), thencompensation of the ECG inputs is circumvented through step 1413. Ifnot, step 1403 selects a first mean QRS vector that is closest to afirst plurality of mean QRS vectors, each corresponding to a QRS complexwith a standard electrode configuration. Step 1405 selects a second meanQRS vector that is closest to a second plurality of mean QRS vectors,each corresponding to a QRS complex with a garment electrodeconfiguration. In step 1407, an angle α between the two selected meanQRS vectors is determined as shown in FIG. 13. In step 1409, an angleΦ−α between the first selected mean QRS vector and a reference axiscorresponding to Lead I is determined. In step 1411, a compensationcoefficient k1 (as given by EQ. 2) is determined. Procedure 1400continues to step 1413 in order to process subsequent samples.

FIG. 14B shows a continuation of flow diagram 1400, in which thecompensation coefficient k1 is used to compensate subsequent ECG samplesobtained from the electrodes positioned on the diagnostic garment. (ECGsamples are acquired every 1/N seconds, i.e., N samples per second. Asample comprises ECG measurements from a plurality of ECG electrodes asshown in FIG. 3.) Step 1415 determines if a new sample is available forLead I (corresponding to LA 1203 minus RA 1201 as shown in FIG. 12) andfor Lead III (corresponding to LL 1205 minus LA 1203 as shown in FIG.12). If so the voltages for Lead I and Lead III are compensated usingEquations 3-6 in step 1417. In Step 1419, the voltage for Lead II isdetermined using EQ. 1B. Steps 1415-1419 are repeated for eachsubsequent ECG sample.

FIG. 15A shows a flow diagram 1500 for compensating for signal noiseresulting from the positioning of ECG electrodes on a diagnostic garmentin accordance with an embodiment of the invention. Process 1500determines compensation coefficient k2 in order to reduce signal noiseinduced by positioning ECG electrodes on the diagnostic garment, e.g.,glove/sleeve 10. Step 1501 determines if all QRS complexes have beenprocessed. If so, step 1509 determines compensation coefficient k2 usingEquation 7. If not, step 1503 processes the next QRS complex.

In step 1505, a modified Lead I value is determined. With step 1507 theheight of the R wave 1005 (as shown in FIG. 10) is determined for bothLead I and the modified Lead I (Mod_Lead I). Process 1500 is repeateduntil all QRS complexes are processed. In step 1511, once compensationcoefficient k2 is determined, process 1500 continues to processsubsequent ECG samples as shown in FIG. 15B.

FIG. 15B shows a continuation of flow diagram 1500. If step 1513determines that a new ECG sample is available for processing, leadpotential VL is calculated with Equation 9 using Lead I and Lead IIIpotentials in step 1515. In step 1517, compensated lead values aredetermined using Equations 10 and 11. Even though Equations 10 and 11compensate for two of the three leads, the third lead can be compensatedin accordance with Equations 1A-1C. Steps 1513-1517 are repeated forsubsequent ECG samples.

With another embodiment of the invention, the methods shown in FIGS.14A, 14B, 15A, and 15B can be combined so that both compensation forelectrode positioning and signal noise can be performed on EEG signalsreceived from a diagnostic garment.

The embodiments shown in FIGS. 14A, 14B, 15A, and 15B exemplifycompensating ECG samples from ECG electrodes that are positioned on adiagnostic garment. However, other embodiments of the invention supportother algorithms to compensate for the ECG electrodes being positioneddifferently from the classical locations as shown in FIG. 1. Otherembodiments of the invention may position ECG electrodes at differentnon-classical locations and correspondingly compensate for shifts in ECGelectrode positioning.

FIG. 16 shows an apparatus 1600 for obtaining, transforming, andcommunicating ECG measurements from electrodes that are positioned on adiagnostic garment in accordance with an embodiment of the invention.Measurement module 1601 obtains ECG inputs (samples) 1651 from ECGelectrodes positioned on the diagnostic garment. In the embodiment,measurement module 1601 includes a buffer to appropriately interface tothe voltage levels of the ECG electrodes and a multiplexer to interfacewith a plurality of ECG electrodes. Because ECG inputs typically haveanalog characteristics, analog to digital converter (ADC) 1603 convertsanalog ECG inputs into a digital format in order to process the ECGsamples.

Processor 1607 may compensate the ECG samples (in accordance withprocesses 1400 and 1500) or may transmit the uncompensated ECG samplesto a remote apparatus (e.g., apparatus 1700) over communications channel1653 through communications module 1605. The embodiment supportsdifferent types of communications channels including wireline channels(e.g., telephone, cable and Internet channels) and wireless channels(e.g., cellular radio channels, point-to-point radio channels, andinfrared point-to-point channels).

FIG. 17 shows an apparatus 1700 of a remote surveillance center forreceiving and processing ECG measurements in accordance with anembodiment of the invention. In the embodiment apparatus 1700 receivesuncompensated samples over communications channel 1653 throughcommunications module 1701. However, with another embodiment of theinvention, apparatus 1600 may compensate ECG samples and send thecompensated samples to apparatus 1700.

Apparatus 1700 receives ECG samples, in which each ECG sample comprisesECG measurements from ECG electrodes positioned on a diagnostic garment.Demultiplexer 1703 separates the ECG measurements and passes them toprocessor 1707 through buffer 1705. Processor 1707 processes the ECGsamples. If the ECG samples are uncompensated, processor 1707compensates the ECG samples in accordance with Equations 2-11.

The processed ECG samples may be stored in storage device 1709 for laterretrieval or may be displayed on display module 1711 for a clinician toview. The clinician configures apparatus 1700 through input module 1713for processing, storing, and displaying processed ECG samples.

As can be appreciated by one skilled in the art, a computer system withan associated computer-readable medium containing instructions forcontrolling the computer system can be utilized to implement theexemplary embodiments that are disclosed herein. The computer system mayinclude at least one computer such as a microprocessor, digital signalprocessor, and associated peripheral electronic circuitry.

Disposable Diagnostic Garment Option

An embodiment of the invention provides a disposable version of theglove by making the glove out of a plastic material that can beinflated. By using an inflatable glove, the contour of the body (e.g.,chest and torso) is automatically matched by the contour of the glove.The matching contours will allow for a close fit between the electrodesand the skin.

The inflation of the glove may be done automatically upon opening apackage containing the glove by use of a one-way valve. The lowerpressure within the glove will cause it to take in enough air to inflatethe glove.

The electrode may be painted or printed on the plastic of the gloveallowing for a low cost method of producing the glove.

The glove may be either two dimensional (i.e. a single seam) or threedimensional (i.e. multiple seams). The two dimensional reduces costwhile the three dimensional version allows more flexibility in adaptingthe glove to the contour of the body.

FIGS. 18-21 illustrate a version of an inflatable glove. The inflatableglove is in the form of a hollow rod 1802 having affixed thereto apreformed series of hollow, molded, elongate, flexible pillow members1804. The pillow members 1804 are separated one from the other by a seamsuch as seam 1806 but connected by a gas flow passage. ECG electrodessuch as electrodes 1830 are provided on the various inflated pillowmembers 1804. Electrodes 1830 are also positioned on opposite ends ofthe carrier rod or stick 1802. As shown in FIG. 18, the separateelectrodes 1830 may include leads or lead wires 1832 connected thereto.The electrodes 1830 are spaced by virtue of their positioning on thediscrete pillow members 1804 to accommodate a desired physicalpositioning or spacing such as would be accomplished by the sleeve andglove depicted in FIG. 3.

A valve 1834 is provided in hollow rod or tube member to effectinflation of the pillow members 1804 of the glove. The opposite side ofthe glove including the rod 1802 as well as the pillow members 1804, mayinclude an appropriate adhesive for maintaining placement of theinflatable glove on the hand of an individual such as illustrated inphantom in FIG. 18.

The uninflated pillow member 1804 of the glove of the type depicted inFIG. 18 may then be folded over the rod when it is originally packagedand upon unpackaging and inflation will assume the configuration such asshown in FIGS. 18-21. The glove may then be placed upon the hand andlower arm of an individual. The glove is typically placed upon the lefthand and lower arm or forearm in the manner depicted for example withrespect to the glove and sleeve of FIGS. 3, 4 and 5. The pillow members1804 may then be inflated by inserting air or a non-toxic gas throughthe valve mechanism 1834 into the rod 1802 and connected pillow members1804.

The device is manufacturable in various sizes. Thus the number of pillowmembers or elements 1804, the length of the rod 1802, the size of thepillow elements 1804 and other dimensional characteristics of thedisclosed glove may be altered in order to accommodate persons havingdifferent physiology. Additionally, the glove may be disposed followinguse. Further, the electrodes 1830 may be affixed to the various pillowsegments 1804 by deposition of a conductive material on the inflatableplastic which is utilized to make the pillow. Likewise the leads 1832may also be affixed by such deposition techniques and connected to asocket assembly 1835 mounted on the rod 1802. Socket assembly 1835 maythen receive a plug (not shown) which connects to a central control unit24.

Alternative aspects and features of the embodiment of FIGS. 18-21include the capability of folding the uninflated pillow members aroundthe rod or stick 1802. Thus the assembly can then be convenientlypackaged in a small box or sealed package for subsequent removal andinflation. The pillow members 1804 may be formed of heat sealed sheetsof plastic material with an air flow channel provided between the pillowmember 1804. The conductive electrodes and leads may be printed on thesurface of the preinflated pillow members 1804 are affixed or moldedinto the material forming the pillow members 1804. The pillow members1804 may have distinct sizes and shapes. The pillow members 1804 mayalso be sectioned so that only discrete portions thereof inflate. Therod 1802 is typically hollow but generally rigid to facilitate manualgripping and proper positioning.

While the invention has been described with respect to specific examplesincluding multiple modes of carrying out the invention, those skilled inthe art will appreciate that there are numerous variations andpermutations of the above described systems and techniques that fallwithin the spirit and scope of the invention as set forth in theappended claims.

What is claimed is:
 1. A disposable diagnostic garment for obtaininghuman electrocardiogram (ECG) input readings comprising, in combination:a garment covering that is inflatable to automatically match a contourof a body portion of a patient, the garment covering including an armportion for a left arm of a patient and an inside palm side; and atleast one electrode that is affixed to the arm portion and inside palmside of the garment covering, wherein the at least one electrode isarranged on the garment covering to position the at least one electrodeagainst the body portion of the patient and to provide a correspondingECG signal when the garment covering is inflated and when the left armis supported with the elbow against the body and the left forearmdirected toward the right shoulder, and wherein the at least oneelectrode comprises RA, RL, V1, V2, V3, V4, V5, V6, LL and LAelectrodes.
 2. The disposable diagnostic garment of claim 1, wherein thegarment covering comprises a hand portion for a left hand of the patientincluding wherein the at least one electrode comprises the RA, RL, V1,and V2 electrode.
 3. The disposable diagnostic garment of claim 1,wherein the at least one electrode is affixed to the garment covering bydepositing a conductive material on the garment covering.
 4. Thedisposable diagnostic garment of claim 1, wherein the garment coveringcomprises a plastic material.
 5. The disposable diagnostic garment ofclaim 1, further comprising: an inflation means for inflating thedisposable diagnostic garment.
 6. The disposable diagnostic garment ofclaim 1, further comprising: a one-way valve for inflating thedisposable diagnostic garment.